Many vibrational apparatus rely upon the rotation of an eccentric. Others rely on pneumatics and/or hydraulics in order to reciprocate a piston which provides a direct output of the vibrational output. Such structures however, whilst disclosed for many end uses, have a downside in that where the device to which the output piston is attached has itself stalled there is a difficulty in ensuring a recommencement of the vibrational output as a consequence of the piston itself refusing to move relative to its cylinder or the equivalent.
Vibrational heads whilst disclosed for many end uses, have a downside in that where the device to which the output piston is attached has itself stalled there is a difficulty in ensuring a recommencement of the vibrational output as a consequence of the piston itself refusing to move relative to its cylinder or the equivalent. Such would be the case with apparatus of PCT/NZ2003/000158 (published as WO 2004/009298) of Bantry Limited.